1. Field of the Invention
The present invention relates to 1,4-dihydropyridine derivatives useful as the preventive and therapeutical agents of ischemic heart disease and hypertension.
2. Description of the Prior Art
There are the prior art 1,4-dihydropyridine derivatives described in Japanese Patent Publication No. 63-5024 and Japanese Patent Kokai No. 60-500255, nifedipine and the like. These compounds have coronary vasodilating activity due to calcium antagonism, and used as the preventive and therapeutical ischemic heart disease and hypertension. However, since these prior art 1,4-dihydropyridine derivatives have even the property to dilate the peripheral vessel due to coronary vasodilating activity, their topical activity is insufficient. Furthermore, these compounds have a drawback of poor duration of action. The compounds described in Japanese Patent Kokai No. 60-500255, while fairly improved in this action, show no increase in action of cyclic GMP (hereinafter referred to as "c-GMP"), and therefore these compounds are insufficiently effective as preventive or therapeutical agents for treatment of hypertension when compared with nitrates such as nitroglycerin. The present inventors have found novel compounds having the selective coronary vasodilating activity and increased activity of c-GMP.